TOPIC: One Scratch

Occasionally I get a film in that has one continual scratch dow the left or right side. Very fine,and sometimes can not be detected unless your looking for it when the movie is being played. What is the cause and can anything be done to get rid of the problem?

I am by no means an expert but it seems to me that once it is scratched it is too late (particularly on the emulsion side). Do you know if it is on the emulsion side? I've heard that Filmguard can remove some minor scratches from the non-emulsion side but I've never experienced it firsthand.

Back when firetrap rollers were still in use this was quite common (and serious), and was usually caused by sharp film scraps shedding off and being caught in the semi-enclosed fire trap... They would carve a scratch on whatever part of the film touched them until they were removed... The firetrap is nearly extinct now, but anything in the film's path that touches or rubs against it can scratch... If the emulsion is scratched it can't be repaired, but light scuffs to the non-emulsion side can sometimes be helped by light careful cleaning with naptha... Use due care, naptha is very flamable...

Almost anything in the film path can cause scratches if it's not operating correctly. However, if you have a stationary scratch, you've got something that the film is touching as it passes over it. Check all of your platter & other film handling rollers. Make sure all are operating freely. Check your pad rollers. On the advice of a tech I use, I converted my rollers to a version that doesn't have a molded "cut" for the sprocket teeth. The inside flange of those old rollers can be a source of scratches... even more so if they are not adjusted properly or rotate freely. Burrs on your aperture plate can cause a continuous scratch, if your gate presses the film too close to it.

Check your fail safe/cue detector. Some of them have rollers that can gum up, stop rolling & develop flat spots.

Film Guard works well for surface scratches. However, if the scratch goes through the emulsion (like with green scratches), you're destroying film... and that needs to be dealt with immediately. Film Guard will not repair this kind of damage.

I agree with RodeoJack. Those longitudinal scratches at the very edges of the image are often due to pad rollers that have rough spots, are not turning, or that have been set improperly.
John P. Pytlak, Senior Technical Specialist
Customer Technical Services
Entertainment Imaging
Research Labs, Building 69, Room 7525A
Eastman Kodak Company
Rochester, NY 14650-1922
Telephone: +1 585-477-5325 Cell: +1 585-781-4036 Fax: +1 585-722-7243
E-Mail:
This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Website: http://www.kodak.com/go/motion

<BLOCKQUOTE><font size="1" face="Verdana, Arial, helvetica">quote:</font><HR>Originally posted by rodeojack:
<B>Almost anything in the film path can cause scratches if it's not operating correctly. However, if you have a stationary scratch, you've got something that the film is touching as it passes over it. Check all of your platter & other film handling rollers. Make sure all are operating freely. Check your pad rollers. On the advice of a tech I use, I converted my rollers to a version that doesn't have a molded "cut" for the sprocket teeth. The inside flange of those old rollers can be a source of scratches... even more so if they are not adjusted properly or rotate freely. Burrs on your aperture plate can cause a continuous scratch, if your gate presses the film too close to it.

Check your fail safe/cue detector. Some of them have rollers that can gum up, stop rolling & develop flat spots.

Film Guard works well for surface scratches. However, if the scratch goes through the emulsion (like with green scratches), you're destroying film... and that needs to be dealt with immediately. Film Guard will not repair this kind of damage.</B><HR></BLOCKQUOTE>

We have one projector that keeps scratching the film. After the first movie(after I started in booth) I check all the rollers to make sure the film isen't up on the edge anywhere.(I was trained that that can cause scratches) I guess now I will check the aperture for burrs. But if someone could explain what I'd be looking for.

The emulsion side of the film is the side where the picture is printed, while the non-emulsion side is clear, like the film base itself...

The aperture plate is the metal plate that slips into place just behind the film gate, through which the light passes before going through the lens... The "flat" plate will have a rectangular opening (aperture) while the "scope" plate will have a nearly square opening...

You don't mention IF you are using a platter, or magazines (reel to reel) but ANYTHING in the film path in either can also scratch the film... Look everthing in the film path over for stuck rollers or pads, and burrs or rough spots... Careful examination should turn up the culprit...

Many times, there will be a buildup of film debris (magenta/purple emulsion particles, white base-side dust) near the component that is causing the scratch.

In some cases, you can run a brand new piece of film (e.g., a trailer), stop the projector, and then carefully examine the film by reflected light to find the location in the film path that the scratch starts.
John P. Pytlak, Senior Technical Specialist
Customer Technical Services
Entertainment Imaging
Research Labs, Building 69, Room 7525A
Eastman Kodak Company
Rochester, NY 14650-1922
Telephone: +1 585-477-5325 Cell: +1 585-781-4036 Fax: +1 585-722-7243
E-Mail:
This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Website: http://www.kodak.com/go/motion